SQL Select 一列的唯一值和另一列的最新值

Question

我有以下 table 结构：

leads:

name  | email | date
-------------------------------------------------------
John  | john@mail.com  | 2020-01-21
J     | john@mail.com  | 2020-01-20
Alex  | alex@mail.com  | 2020-01-19
A     | alex@mail.com  | 2020-01-18
James | james@mail.com | 2020-01-17

我只需要 select 具有唯一电子邮件和最新关联名称的行，因此预期结果是：

name  | email | date
-------------------------------------------------------
John  | john@mail.com  | 2020-01-21
Alex  | alex@mail.com  | 2020-01-19
James | james@mail.com | 2020-01-17

Answer 1

使用不存在

select * from tbl a 
where not exist(select 1 from tbl b where a.email = b.email  and a.date < b.date)

SQL Select 一列的唯一值和另一列的最新值

SQL Select unique values by one column with the latest value by another column

mysql

sql

greatest-n-per-group